Spark plug electrode



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SPARK PLUG ELECTRODE' Filed June 7' 1949 By this Ineans the tip of the insulator is pro tected from excessive heat shock which might cause fracture and from attaining Sufcient1y high temperatures to cause preignition' vvhat is claimed is:

1' In c0mbination, a spark plug insulator having a centra1 bore therein, an electrode in the bore c10sing the 10Wer end thereof and having a reduced portion extending upwardly therein, said electrode being provided at a p0int sub- Stantia1ly removed from the 10Wer end of the bore With 3 Tadia11y enlarged portion engaging the inner wal1 0f the bore and centering the e1ectrode therein, said enlarged portion having periphera1 Surfaces radiauy spaced from said wa11 to p1'0vide communication between the reduced portion 0f Said electrode and the space in Said boTe above Said enlarged portion and good heat conducting meta1 Substantia11y 1ling the space between the reduced portion of the e1ectrode and the bore.

2 In the con1bination as clairned in claim 1, Said insulator having an u per ortion of the bore en1arged, providing a Seat at the junction With the 10Wel' portion Of the bore, the upper enlarged portion 0f said e1ectrode being engaged with the seat at circunferentia11y spaced points.

3' In a Spark plug, a spark plug insulator hav ing a centra1 bore comprising a portion of sma11 dianete1' adjacent the tip 0f the insulator vvhich is normany exposed in the c0mbustion chanber, and a portion of enlarged diarneter spaced there fr0!n, an electrode C0Tnprising a core 0f heat resistant Ineta1 in the bore having an intermediate portion of 1ess diameter than the bore and enlarged ends, 0ne of said enlarged ends being 10cated at the tip of the insulator and sub- Stantia11y 1'111ing the bore, the 0her en1arged end engaging the portion of the bore 0f enlarged diameter for centering the core therein and having a periphera1 portion Ten10ved fron1 the other enlarged end to provide con1n1unication between said bore portion of SIna11 dialneter and said bore portion of enlarged diameter, and Ineta1 of g00d heat conductivity surrounding the 1'e duced portion of the c01'e and nuing the said bore portion of snla11 diameter and p10viding a path of high heat conductivity for the 1oW of heat away from the tip of the insu1ato1" 4 In a spark plug, the combination of a spark plug insulator having a centra1 bore including an upper enlaTged portion connected With a lower p0rtion by a conica1 Seat, an electrode having a partia11y conica1 head engaging the seat, said head having opposite1y disposed flat Surfaces inward1y Spaced from said Conica1 seat to provide 00Tnrnunication between Said upper and lowel' porti0ns and a shank of ]ess diamete1' than the bore extending d0wnwardly thereffom said shank being rovided at the lowe1 end of the b01 e with an enlarged portion uing the bo1e end With an extension serving as a center electrode, the space between the shank portion 0f the electrode and the wa11 Of the bore being mled with metal of high heat c0nductivity WILFRED A- BYCHINSKY REFEEENCES CITED The f0110wing references are 0f record in the 1e of this patent;

UNITED STATES PATENTS Number N arne l:)te

2,318,922 Carington 1/ay 11, 1943 2,49,403 McDouga1 Sept 1 1948 

